Breadcrumbs

If you are not using the proper technique you will get sore. The entire playing mechanism which includes the wrists, forearms, elbows and the shoulders should be relaxed. It should never be tense. How do you relax while playing a difficult piece in mind,say a Liszt Etude?
One answer to that would be a sigh. Yes,a sigh. A sigh effectively relaxes muscles and reduces tension in areas where you might not even realize you are tensing.